In a study done between May and November, it was discovered that not only did relatively few people make use of online office suites, those who did also used a far less diverse suite of functions and don't see these online suites as “competition” for standard office apps right now. Still, the number of people making actual use of online office programs was zero not long ago.
This is the second study done in recent history which demonstrates how few people are using online office suites. Some may look at it as bad, but I see it in a different light. Google Docs, for example, has an extremely small set of tools available to it. A document or spreadsheet editor from 15 years ago would be far more functional. The fact people are making use of it at all shows their willingness to experiment and I think the only real hurdle Google and others have to overcome, aside from the trust factor, is feature richness. Every once in a while I will login to Google Docs and see they've added some new feature – and with every feature they add, more users will come.